1. Field of the Invention
The present invention relates to a data processing apparatus for recording information data by using a recording medium which needs data erasing processing before recording of data.
2. Description of the Related Art
Some conventional types of commercially available electronic still cameras are capable of recording a still image by using as a recording medium a memory card having a solid-state memory element. Other types of electronic apparatus capable of using such a memory card, such as pocket-size personal organizers and portable computers, have also been commercially available.
In many cases, a flash memory which is readable, erasable and writable is used for such a memory card.
The flash memory is randomly writable, but needs a data erasing operation before recording of data. Specifically, since the flash memory has the characteristic that overwritten data is impossible to reproduce, it is necessary to record new data in an area after erasing old data recorded in that area.
The flash memory is impossible to permanently use, and has definite durability determined by the number of repetitions of a data recording/erasing operation.
To impart as long-term durability as possible to the flash memory having definite durability determined by the number of repetitions of a data recording/erasing operation, it has been proposed to adopt a recording method which includes the process of performing xe2x80x9cerasurexe2x86x92recordingxe2x86x92verification of recordingxe2x80x9d in units of a sector (512 bytes) which will be described later, i.e., the steps of erasing an area of a recording medium in which to record data before recording the data, recording the data in the erased area of the recording medium by the application of minimum recording current which enables data recording, and verifying whether the data has been securely recorded in the erased area of the recording medium.
Not only the flash memory but also an EEPROM (electrically erasable programmable read-only memory), a magneto-optical disk and the like are typical examples of the aforesaid recording medium which needs an erasing operation before recording.
For this reason, an apparatus of the type employing the recording medium which needs an erasing operation before recording, for example an electronic still camera, needs to repeatedly perform the recording operation of erasing data from a recording-enable area on the recording medium (in units of a sector), then recording image data for one photographic picture in the erased area by a maximum allowable amount which can be stored in the erased area, and then verifying the status of the recorded image data. The apparatus continues such recording operation until all the image data for one photographic picture is completely recorded on the recording medium.
The apparatus of the aforesaid type, therefore, offers the problem that a user may miss photographic timing owing to the wasteful time taken to record image data on the recording medium. This problem of recording timing takes place in not only the electronic still camera but also any type of recording apparatus employing the recording medium which needs an erasing operation before recording. In addition, it is necessary to arrange the recording apparatus so that it can quickly detect a recording-enable area on the recording medium and determine whether the recording-enable area is an erased area.
In addition, instead of the above-described recording operation which takes the wasteful time, it is also possible to adopt a method of recording data in an empty area (erased area) of the recording medium by the application of recording current which is regulated so as to permit the data to be securely recorded in a single recording cycle. This method, however, decreases the durability of the recording medium and also causes the problem that a recording-disable area occurs on the recording medium.
It is, therefore, an object of the present invention to provide an improvement in a data processing apparatus using a recording medium which needs to be subjected to an erasing operation before recording of information data, more particularly, a recording medium and a recording unit as well as a data processing apparatus which can cooperatively operate to record information data without delay.
To achieve the above object, in accordance with one aspect of the present invention, there is provided a recording medium which comprises a first recording area in which to record information data and a second recording area in which to record data indicative of a data-erased area in the first recording area.
To achieve the above object, in accordance with another aspect of the present invention, there is provided a recording unit which comprises a recording medium incapable of being overwritten and controlling means for detecting whether a predetermined area on the recording medium is a data-erased area.
To achieve the above object, in accordance with another aspect of the present invention, there is a data processing apparatus which comprises inputting means for inputting information data, recording means for recording the information data on a recording medium which needs to be subjected to an information-data erasing operation before the information data is recorded on the recording medium, erasing means for erasing unnecessary information data from the recording medium, and controlling means for executing control to cause the erasing means to erase the unnecessary information data from the recording medium while the recording means is not performing recording.
To achieve the above object, in accordance with another aspect of the present invention, there is a data processing apparatus which comprises a recording medium which needs to be subjected to an erasing operation before recording of information data, recording means for recording the information data in a predetermined area of the recording medium, detecting means for detecting whether the predetermined area of the recording medium is an erased area, erasing means for erasing information data recorded on the recording medium, and controlling means for controlling the erasing means according to an output of the detecting means.
Another object of the present invention is to provide a recording medium of improved durability and a recording unit which can record information data in a reduced time as well as a data processing apparatus using such recording medium and recording unit.
To achieve the above object, in accordance with another aspect of the present invention, there is provided a recording unit which comprises a recording medium on which to record information data, detecting means for detecting durability of the recording medium, and controlling means for controlling access to the recording medium according to an output of the detecting means.
To achieve the above object, in accordance with another aspect of the present invention, there is provided a data processing apparatus which comprises inputting means for inputting information data, access means for performing access to a recording medium to record the information data, detecting means for detecting durability of the recording medium, and controlling means for controlling the access of the access means according to an output of the detecting means.